How often you should wash your sheets (and how to get them really clean)

You should probably change your bedsheets once a week. Think about it: You spend hours in bed every night, and your sheets collect skin flakes and an assortment of bodily fluids and oils. Then there's stuff like dust, dust mites, and (if you have a cat or dog) pet hair.

Washing your sheets regularly rids them of that gross gunk. But just as important as how often you wash is how you wash them. Do it right and you'll extend your sheets' life — and ensure they get really clean.

Why once a week?

This is universal advice from most expert sources, including Martha Stewart and Good Housekeeping. If your life is busy, changing the sheets weekly might seem like a hassle, and it's a task that can be quickly forgotten. But considering that you likely spend one-third of your life in bed, keeping the sheets clean is worth it.

Treat stains before washing

If there are noticeable stains on your sheets, pretreat them with a spot remover. You can also spray the stained area after you strip the sheets off your bed, and then just toss them into your dirty-clothes hamper until you're ready to wash them.

For tougher stains, like blood, coffee, or wine (we're not above sipping a glass in bed while watching trashy TV), soak the area with OxiClean. Then leave it to penetrate overnight, before putting your sheets in the washing machine. Dish soap works well to remove grease stains from food. Use it the same way you would any other spot remover.

Wash with low temps

Cold water is ideal, but if you're dealing with stains, you may need to use warm water. Hot water can be used to disinfect bedding after an illness or potty-training accident, or to get rid of allergens like dust mites.

In her book "Laundry," Cheryl Mendelson suggests avoiding sheets that have fussy care instructions. "Your everyday sheets, especially those on infants' and children's beds, should be easy to launder vigorously and should never require gentle or complicated treatment."

What about bleach?

If you want to bleach your sheets to get rid of stains, buy white sheets and — for a brightening boost — using color-safe bleach or oxygen bleach on a warmer setting.

If you or your child has extremely sensitive skin, you may want to take an extra step when washing new sheets. Some resin treatments meant to reduce wrinkling in fabric contain small amounts of formaldehyde, which can cause contact dermatitis. If you're concerned about factory finishes, you can remove some of these substances by adding ¼ cup of white vinegar to the wash cycle.

Avoid softeners

Try to avoid using fabric softeners and dryer sheets. Softeners leave residue that decreases the fabric's breathability and absorbency. And if that residue builds up over time, you may end up feeling overheated in your sheets.

Always dry on low